Scientists are now able to view and study hundreds of new galaxies previously inaccessible because they are located in the Zone of Avoidance, a portion of the universe obscured from view by the stars and dust in the Milky Way. The study, conducted by the International Centre for Radio Astronomy Research (ICRAR), was an effort that included scientists from Australia, South Africa, the United States and the Netherlands. The study's findings were published Feb. 9 in The Astronomical Journal.
Using the Commonwealth Scientific and Industrial Research Organization (CSIRO)'s Parkes radio telescope in Australia, scientists were able to view 883 galaxies, a third of which had never been seen before. To see through the Milky Way’s stardust, which blocks up to 20 percent of our view, scientists added an 8.3-inch multi-beam receiver to the telescope. CSIRO's Dr. Bärbel Koribalski explains how the receiver made their study possible: “With the 21-cm multi-beam receiver on Parkes, we’re able to map the sky 13 times faster than we could before and make new discoveries at a much greater rate.” A video provided by ICRAR shows how the telescope viewed the area by observing radio waves.
Scientists now have access to a large number of previously unknown stars and other objects, which are only 250 million light-years away, which is relatively close to the Milky Way in astronomical terms. This new information could help scientists further understand not only the behavior of our own galaxy but also other phenomena in the universe that seem to be affecting it. According to professor Renée Kraan-Korteweg, an astronomer at the University of Cape Town, “An average galaxy contains 100 billion stars, so finding hundreds of new galaxies hidden behind the Milky Way points to a lot of mass we didn't know about until now.”
Scientists also hope that studying the newly found galaxies will help them understand the Great Attractor, a mysterious region in space that exists within the Zone of Avoidance. It's a gravity anomaly discovered in the 1970s with its location pinpointed in the 1980s. According to ICRAR, the Great Attractor “appears to be drawing the Milky Way and hundreds of thousands of other galaxies towards it with a gravitational force equivalent to a million billion suns.”
Now that scientists are able to see into the Zone of Avoidance, they hope to further understand the structures that might be a part of the Great Attractor. ICRAR’s Dr. Lister Staveley-Smith explains: “We know that in this region there are a few very large collections of galaxies we call clusters or superclusters, and our whole Milky Way is moving towards them at more than 2 million kilometres per hour.” So, not only is the expansion of the universe influencing the movement of our galaxy, but so too is the pull of the Great Attractor.
With the information provided by ICRAR’s study, scientists may learn why our galaxy behaves the way it does and unlock other mysteries of the universe.